1. Field of the Invention
The present invention relates to a technical field of an electrical connection system, particularly, an electrical connection system comprising a second component provided with a latch element in which an electrical contact of a first component is shorted out when the first component and the second component is not properly electrically connected while shorting of the above electrical contact is canceled when the first and second components are electrically connected.
2. Description of the Related Art
There is conventionally known a connection system comprising two components respectively provided with a pair of electrical connector elements (a plug and a jack, for example), the connection system being arranged so that connection between the plug and the jack would allow the electrical connector elements to be electrically connected to each other. There is also known a connection system having a jack with a shorting element in which the above-mentioned pair of connector elements can be electrically shorted with each other when a plug is not connected with the jack.
Furthermore, there is known a structure comprising a latch element on a plug side. The latch element may be latched at a first latch position when the plug is separated from the jack while pushed. A second latch position is characterized by the plug being completely engaged with the jack so that the above-mentioned shorting element cancels the shorting, and in which mechanical locking is achieved so that the plug would not come out from the jack. Such a structure is disclosed in U.S. Pat. No. 5,314,345 and JP 2,647,335, for example.
The above-mentioned structure can be effectively used in a repeater device repeating a signal for operating an air bag system of a vehicle. For example, the above-mentioned structure may function as a connecting device for connecting the repeater device and a controller device.
The air bag system comprises an air bag assembly mounted in a driving room of a vehicle, an electrical or electronic controller device, and a repeater device. In a general way of mounting such air bag system, the air bag assembly, the controller device, and the repeater device are first separately mounted to a vehicle. Then, (A) the controller device and the repeater device and (B) the repeater device and the air bag assembly are electrically connected by means of a wire harness.
In a structure in which the controller device and the repeater device are connected as described in (A), the above plug is mounted to one end of a pair of wire harnesses. The other end of the pair of wire harnesses is connected to the controller device. Conductors of the pair of wire harnesses are connected to a pair of terminals of the plug (electrical connector elements), respectively. The above-mentioned jack having a pair of terminals (electrical connector elements) is provided on the same side as the repeater device.
In accordance with the above structure, an easy operation of inserting a plug into a jack connects the controller device to the repeater device. The pair of terminals on the jack side can be electrically shorted by the above shorting element when the plug is not inserted into the jack. Shorting the pair of terminals during installation of an air bag system in a vehicle prevents the leak of charges and flow of current to the air bag assembly side caused by incorrect connection, which can accidentally cause the air bag assembly to open.
Changing the latch position of the latch element after the plug is inserted into and engaged with the jack cancels the shorting and mechanically locks the plug and the jack. Thus, the electrical connection between the controller device and the repeater device is stably secured.
When used as a repeating device, the above structure may, for example, function as a switch for switching an air bag between operation and non-operation.
That is to say, a structure capable of switching an air bag between operation and non-operation is required in some cases due to any circumstances such as legal restriction. In such case, providing a switch as a repeating device in a connecting circuit between the controller device and the air bag assembly allows an air bag operation signal from the controller device to be intercepted from the air bag assembly when the switch is switched to an OFF side. Non-operation of an air bag can be thus achieved.
A structure in which such switching function is directly provided in the controller device can also be considered. In this case, a repeater device as mentioned above is not necessary. An advantage in using a repeater device as described above is that a conventional controller device having no switching function as described above can be used as it is without the need to change the design of the controller device.
As described above, the shorting element is for preventing an accidental operation of the air bag assembly before inserting a plug into a jack. Therefore, shorting between the terminals by means of the shorting element should be canceled after the plug is inserted into and engaged with the jack. That is to say, the above latch element is necessarily moved to the second latch position after the plug is inserted into the jack.
The latch element is typically a small component and, as a result, it is difficult to check whether the latch element is at the second latch position. Therefore, cancellation of shorting is often forgotten. When it is found in inspection that shorting has not been canceled after subsequent assembling work has been performed, what has been assembled must be disassembled in order to access to the plug. This requires a reassembling operation after moving the latch element to the second latch position, which causes a great trouble.